We're a 2-person, 0-car-commute household. I take the bus or walk (bus is almost fully subsidized by my employer), DH bikes every day rain or shine. It seemed silly to have two cars (still a fairly recent MMM convert here), but I put off doing anything about it.
Come to find out that MIL needs a car (hers has been on its last legs for over a year) and, being naturally mustachian, she wants a cheap old reliable car but all the local dealers have only 5-year-old or newer models.
So we're giving her my car for Xmas. It's a beat-up 2001 Impreza with 130K miles. She's happy, we're happy. It cost $500 to service it one last time (hey, it's DH's mom, don't want to saddle her with maintenance we should have done), and never again. I'm looking forward to calling the insurance company once it arrives at her doorstep and removing that thing once and for all.
I told my sisters about it. One of them said, woo-hoo you'll be fine we have only one car too (and they even have a toddler; DH and I don't have kids). The other said, hm, we just upgraded to a bigger 2nd car because of our toddler. Guess which one has read MMM.
Anyway, a year ago if you'd asked me if we could have only one car I'd have laughed. Thanks MMM. :)